South Africa’s move from JIBAR to ZARONIA is being treated by many market participants as a benchmark reform project. That understates the moment. JIBAR will be permanently discontinued immediately after its final publication on 31 December 2026, and the “No new JIBAR” milestone date of 1 May 2026 is intended to stop the creation of new JIBAR-linked exposures ahead of cessation. For corporate issuers, this transition is about far more than the rate referenced in a loan, note or derivative. It will test whether treasury functions are disciplined enough to operate in a market where evidence, control and auditability matter as much as pricing.
The uncomfortable view, and the one issuers should take seriously, is that ZARONIA will expose the organisations still running critical debt administration on spreadsheets, inboxes and the institutional memory of a few trusted people. These tools may have worked when benchmark conventions were simpler and interest calculations were known upfront. They are far less defensible in a market moving towards compounded overnight rates, more scrutiny and tighter expectations from investors, lenders, auditors and boards.
The scale of the issue makes the governance question impossible to ignore. Speaking at the MPG Conference 2025, Rashad Cassim put domestic JIBAR-linked exposure at about R43 trillion as of mid-2025, with offshore exposure estimated at more than R107 trillion. He noted that ZARONIA adoption has accelerated too, rising from R6.4 billion to more than R200 billion. These numbers show that the transition is no longer theoretical. It is already moving through the financial system, and any weakness in the operating model behind debt servicing will be exposed at scale.
That is why this is a financial market story, not an operational footnote. JIBAR gave the market a forward-looking rate known at the start of an interest period. ZARONIA is a backward-looking overnight rate, based on actual transactions and published by the South African Reserve Bank. The benchmark may be more robust, but it also places more pressure on the processes behind every coupon, reset, notice and payment.
The question is not whether treasury teams can perform the calculation. Most can. The question is whether they can prove, under scrutiny, which data source was used, who checked the calculation, what approvals were applied, when investor notices were sent, whether payment instructions matched the final output, and whether the same answer can be reproduced long after settlement.
We are already seeing leading organisations use the transition as an opportunity to reassess their treasury operating models. The conversation is increasingly moving beyond benchmark reform towards questions of governance, auditability, operational resilience and control. In many cases, the objective is not simply compliance with a new rate, but building a more scalable and defensible approach to debt administration.
Ultimately, capital markets do not only price financial performance – they price confidence. Confidence is enhanced through evidence, controls and the ability to demonstrate that obligations are being administered reliably.
This is where the risk sits. In many organisations, the same people source benchmark data, prepare calculations, validate outputs, circulate notices and initiate payment instructions. That concentration of responsibility may be familiar, but it is not strong governance. When those steps sit across spreadsheets, manual reconciliations and email approvals, a missed control is not just an internal issue. It can become an investor confidence issue.
That is the point financial markets should care about. Funding confidence is not built only at issuance, when a book is closed and the pricing is announced. It is built in the less visible discipline of servicing debt accurately, transparently and on time.
South Africa’s debt markets already understand this principle. The local municipal debt market offers a powerful reminder that access to capital is influenced by more than assets and revenue streams. Investors also assess governance quality, operational capability and institutional credibility. Corporate issuers should not assume they are exempt from the same judgement. Weak treasury governance creates uncertainty, and uncertainty has a way of finding its way into price, appetite and trust.
There is also a broader lesson from global benchmark reform. The move away from LIBOR, which the Bank of England notes was once referenced by more than US$350 trillion in financial instruments globally, was not only a legal documentation exercise. It forced institutions to confront the quality of their data, systems, controls and accountability. South Africa is now in the same implementation phase. Treating ZARONIA as a compliance deadline would be the wrong response. The real opportunity is to use the transition to strengthen the operating model behind the funding programme.
For issuers, this means moving beyond legal fallback language and spreadsheet workarounds. It means controlled benchmark data, independently verifiable calculations, segregation between preparation, approval and execution, automated audit trails, and clear governance over every step from rate capture to investor communication and payment. These are not administrative upgrades. They are market credibility upgrades.
Encouragingly, these capabilities no longer require large institutional treasury teams. Increasingly, they can be embedded into the operating model through specialised governance, administration and technology solutions.
Spreadsheets are not the enemy. They are a warning sign that some treasury operating models were built for a less demanding era. ZARONIA will make that visible. Once the market moves past the mechanics of transition, the issuers that stand out will be those that can show their debt servicing is not only accurate, but controlled, repeatable and defensible. The good news is that these are governance challenges that can be addressed. Organisations that act early will be better positioned to strengthen investor confidence, improve operational resilience and build more scalable funding relationships.
In the South African market, where confidence increasingly influences access to capital, governance is no longer an administrative consideration. It is a strategic one.
About the author
Yushavia joined Intengo Market in May 2024, bringing a wealth of capital markets experience and a strong track record as a former PwC partner. As COO of Intengo Market, she focuses on navigating and enhancing the operational landscape and translating the firm’s strategic direction into tangible growth.
Over the last decade, Yushavia specialised in advising clients on merger and acquisition transactions, with a particular focus on financial due diligence. During this time, she also spent a couple of years in the Netherlands gaining exposure to the European Union financial markets.
Yushavia is a qualified Chartered Accountant (South Africa) and holds a BCom (Hons) in Accounting from the University of KwaZulu-Natal. Outside of work, she is a part-time, budding bird watcher and enjoys spending time in the South African bush.
